Vladimir Putin, after eight years as president of Russia and four more as prime minister, is stubbornly holding on to power. He has announced his intention to return as president and declared his party the winner in parliamentary elections that are widely seen as fraudulent. In Moscow 100,000 protesters have taken to the streets in the largest demonstrations since Putin took office.
Putin began his career as a KGB spy but when he became president, he made himself a valued ally of the West. How did he do it? And what made Washington and London turn against him?
The final episode of the series tells the inside story of two relationships: Barack Obama's campaign to win over Russia's new President Dmitry Medvedev, and Medvedev's own complex dealings with Vladimir Putin.
Obama became president determined to rid the world of nuclear weapons. To begin the process he needed Russian help. So he set out to reset relations with Russia. Ignoring Putin, whom many considered still in charge, he concentrated on Medvedev.
Top officials on both sides take viewers deep inside the negotiations. They describe how a phone call between the two young lawyer-presidents finally clinched the agreement - which cut their countries' nuclear arsenals in half.
But inside Russia, Medvedev had a harder time. He responded to the 2008 global financial crisis by setting out to make Russia into a modern democratic economy. He made little progress. He told Obama that Russia's most famous dissident, Mikhail Khodorkovsky, would get a fair trial. It did not happen.
In the end, Medvedev stepped aside and nominated Putin to be their party's presidential candidate for the 2012 election. Top Kremlin insiders, including Medvedev and Putin, tell how the deal was done - and how it set in train a process that made Vladimir Putin look vulnerable for the first time.